Technical Field
The present disclosure relates generally to pulse tube refrigerators, including pulse tube cryogenic coolers, and more specifically to pulse tube refrigerators equipped with reservoirs and inertance tubes.
Background Art
Pulse Tube Refrigerators (“PTRs”) play an important role in satisfying the need for cryogenic cooling of space-based infrared detectors as well as many other applications requiring coolers with high reliability, low vibration and high efficiency. PTRs employ three types of phase shifting processes to control the phase shift between the mass flow and pressure. The most conventional is used in Orifice Pulse Tube Refrigerators (“OPTRs”), wherein the mass flow and pressure are in phase at the orifice. In Double Inlet Pulse Tube Refrigerators (“DIPTRs”), a bypass valve between the warm end of the pulse tube and the warm end of the regenerator provides phase shifting. In Inertance Tube Pulse Tube Refrigerators (“ITPTRs”), which are the focus of this innovation, phase shifting is controlled by an inertance tube replacing the orifice.